The Syrian Observatory for Human Rights said on Saturday the overnight shelling from the US-run base in al-Omal oil field targeted farms controlled by the IS group in the eastern countryside of Deir al-Zour province.

The death toll could likely rise due to the number of critically wounded people, reported Xinhua news agency.

The shelling comes as the IS group has lost all villages and towns in the eastern Euphrates region and is now controlling a few farms in that area.

The Observatory said that around 1,250 IS militants have been killed since the U.S.-backed Syrian Democratic Force (SDF) launched a wide-scale offensive to defeat IS in the eastern Euphrates region last September.